As a D50 user as well, I hope I might be able to help a little.
When I am using the 18-55mm kit lens for landscapes or seascapes I will not go above f16, I find f8 doesn'f really give enough sharpness from front to back in a wide angle shot and above F16 the sharpness drops off a lot, possibly from camera shake due to the longer exposure times.
I will always use a tripod and because the D50 doesn't have a mirror lock up facility for taking pictures (just for sensor ceaning) I will trip the shutter using a remote shutter release, I found the Nikon remote infra red device great for this and picked one up cheap from ebay (£3 + p&p new from Hong Kong).
I also found that not using the lens at 18mm helps the sharpness a little as well, I usually go no wider that 20mm.
When I am using f16 I try to pick a focal point just about a third of the way into the scene, looking at your shot perhaps the fallen red leaves on the path would be about the right focal point for this instance.
An example of the settings I have mentioned above can be seen in a shot on page 4 of my portfolio, titled Bas Fors.
There was a brisk breeze blowing off the loch when this was taken, so I set the tripod down really low to give more stability.
The focal point for this shot was the smaller boulder in the loch, just left of centre, between the two larger boulders.
I hope this all makes sense, and helps you a little.